Here are three that "make my eyes water" as Twisterdog puts it!

The people that or the person that...should be who..."the people who"

"That's where it's at" no,no,no..."that's where it is!" I blame this one on advertising. The "at" is both unnecessary and incorrect.

Myself If you use it, chances are it is used incorrectly! Me is not a bad word and is often the correct word. "Get back to John or me" is correct. "Get back to John or myself" is not correct!

You would not (I hope) say "get back to myself" you would say "get back to me."

Usually, if used correctly the "myself" can be taken out of the sentence without loss of meaning as in "Please mother, I'd rather do it myself!" If you said, "Please mother, I'd rather do it!" meaning is not lost.

There, my eyes have cleared and I feel better!